5.9 Case Study - Aircraft Emergency Stopping System

The aircraft emergency stopping system is used to bring the aircraft to a halt on runway in case of aborted take-off or landing emergencies. The system aids the aircraft to halt its forward momentum with minimum damage to aircraft or injury to pilot. The major subsystems of the system are:

• Engagement System

  • Multiple element net assembly

  • Shear pin

  • Shear off coupling

  • Purchase tape

• Engagement System support

  • Suspension cable

  • Suspension cable anchor

  • Chain and shackle

  • Net anchors

  • Ferrule

• Stanchion System

  • Stanchion frame assembly

  • Base frame assembly

  • Motor and winch assembly

• Tape connector

• Energy absorber

• Pressure roller assembly

• Sheave assembly

• Tape retrieval system

• Electrical control system

  • Main control panel

  • Remote control panel

• Foundation

When an emergency landing is requested, a command is issued from the air traffic control tower. This command is received through the remote control located in the traffic control tower and the multiple element net assembly is raised with the help of stanchion system. As the net envelopes the aircraft, the pull exerted on the net releases the net anchors and breaks the shear pins in the shear off couplings, releasing the net top from the suspension system. The purchase tapes attached to the net end loops are pulled through the fair lead tubes and begin paying off the two energy absorber tape drums, thereby turning the rotary hydraulic brakes. This action generates a uniform braking force which smoothly decelerates the aircraft to a safe stop.

After the aircraft has been...